Renkus-Heinz beam steering improves sound under synagogue dome

A recent Renkus-Heinz installation at a synagogue in Philadephia has improved clarity and consistency of audio within the building, particularly under the domed ceiling.

The sanctuary at the Rodeph Shalom synagogue seats about 1,400 and includes a large balcony area. The walls are painted with gold leaf dating from the building’s construction in 1928, and the domed ceiling towers 18m above. The house of worship hosts a wide range of speakers and events, from small ceremonies to packed High Holidays services. Sabbath services are contemporary, with nine or more musicians and sometimes a choir. So the new system had to deliver full-range music as well as clear, intelligible speech.

Acoustics, AV and vibration consulting firm Acentech was brought in to design the new system. “The biggest challenge was the shape of the space and the dome,” explained Acentech senior consultant Perry Artese. “The room is very live, and we had to deal with cancellation under the dome and a lot of flutter echo. We studied the acoustics, and the reverb time was not bad but the speech transmission index ranged from 0.51 to 0.55, which is just fair, so it was hard to discern speech.”

“The old horn-loaded sound system created too much splash and echo,” added Walter Mosetter of audio/video systems supplier Philadelphia Sound, who handled the system programming and interfacing. “We weren’t looking for volume so much as clarity and consistent coverage, without over-energising the room.”

Acoustic treatment was unfeasible because of aesthetic and architectural considerations – the building is on US’s National Register of Historic Places. Fortunately, beam steering provided the solution.

“We tested several systems,” recalled Mosetter, “and what we found with the Renkus-Heinz IC Live was that not only did it sound better, but the beam-steering technology gave us much more control.”

“A lot of issues went away with beam steering,” added Philadelphia sound senior project manager Raymond Stokes, who designed the wiring and power layout – and also mixes weekly services for Rodeph Shalom. “We could place the sound precisely, eliminate reflections, reduce overall volume, and get clarity and coverage everywhere.”

The team opted for a pair of Renkus-Heinz Iconyx IC Live ICL-FR triple stack arrays. “The acoustic models showed us we could achieve a considerable SPL throughout the sanctuary,” said Artese. “The triple stacks gave us more than enough power and even more control over the beams than a double stack. The two IC212S-FR subwoofers are used for some events but often the arrays are more than sufficient.” DSP is provided by a BSS Soundwave London system.

The loudspeakers are mounted to steel columns. “The columns provide enough offset that they look like the speakers belong in the space instead of being stuck on a wall,” noted Mosetter. “This worked with the aesthetics of the architecture so everyone is happy, and it let us place the speakers optimally, making tuning the system easier.”

Walter Mosetter summed up the installation: “It was a challenging project and a challenging space, but the Renkus-Heinz IC Live system was really an ideal solution.”